In modern fire fighting systems, it is still the custom, for example, in fighting a fire several thousand feet from a hydrant, to drop a distributor ball valve at the fire and start laying a four inch hose line from the fire to the source of water which may be a hydrant or a pond. The hydrant may be a 600 gallon per minute, 60 psi type which will be reduced to about 350 gallons per minute at the fire due to line loss, friction, etc. If a Siamese valve is interposed in the lay, a fire engine pump may be used to supplement hydrant pressure, thereby providing 150 psi and increasing the flow at the fire to 600 gallons per minute.
If it becomes necessary to tie in a second fire engine pump, it has been necessary to shut down the flow while another Siamese valve is interposed in the line thereby taking in air which may cause air hammer or cause the first pump to fail and permitting the fire to develop during the down time.
In various fixed pumped installations, there have been manual valve systems which permit one pump to boost a second pump as in U.S. Pat. No. 1,523,342 to Hart of Jan. 13, 1925, wherein the flow is reversible. Similarly, in U.S. Pat. No. 2,134,409 to Kirgan of Oct. 25, 1938, a refrigeration system, with a pair of pumps affixed on a compressor tank, includes a manual valve system for by-passing one of the condensers, the pair of clappers being manually moved by knobs.
As far as I am aware, no previous valve systems have been suggested for use in portable, vehicular fire engine equipment wherein a valve coupled into an elongated flexible hose lay, can be used for quick attachment of a booster pump without air intake, or flow interruption, to compensate for loss of pressure and to provide increased pressure.